armsrc/BigBuf.c

   1 //-----------------------------------------------------------------------------
   2 // Jonathan Westhues, Aug 2005
   3 // Gerhard de Koning Gans, April 2008, May 2011
   4 //
   5 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   6 // at your option, any later version. See the LICENSE.txt file for the text of
   7 // the license.
   8 //-----------------------------------------------------------------------------
   9 // BigBuf and functions to allocate/free parts of it.
  10 //-----------------------------------------------------------------------------
  11
  12 #include <stdint.h>
  13 #include "proxmark3.h"
  14 #include "apps.h"
  15 #include "string.h"
  16
  17 // BigBuf is the large multi-purpose buffer, typically used to hold A/D samples or traces.
  18 // Also used to hold various smaller buffers and the Mifare Emulator Memory.
  19
  20 // declare it as uint32_t to achieve alignment to 4 Byte boundary
  21 static uint32_t BigBuf[BIGBUF_SIZE/sizeof(uint32_t)];
  22
  23 // High memory mark
  24 static uint16_t BigBuf_hi = BIGBUF_SIZE;
  25
  26 // pointer to the emulator memory.
  27 static uint8_t *emulator_memory = NULL;
  28
  29 // trace related variables
  30 static uint16_t traceLen = 0;
  31 int tracing = 1; //Last global one.. todo static?
  32
  33 // get the address of BigBuf
  34 uint8_t *BigBuf_get_addr(void)
  35 {
  36         return (uint8_t *)BigBuf;
  37 }
  38
  39
  40 // get the address of the emulator memory. Allocate part of Bigbuf for it, if not yet done
  41 uint8_t *BigBuf_get_EM_addr(void)
  42 {
  43         if (emulator_memory == NULL) {          // not yet allocated
  44                 emulator_memory = BigBuf_malloc(CARD_MEMORY_SIZE);
  45         }
  46
  47         return emulator_memory;
  48 }
  49
  50
  51 // clear ALL of BigBuf
  52 void BigBuf_Clear(void)
  53 {
  54         memset(BigBuf,0,BIGBUF_SIZE);
  55         Dbprintf("Buffer cleared (%i bytes)",BIGBUF_SIZE);
  56 }
  57
  58
  59 // allocate a chunk of memory from BigBuf. We allocate high memory first. The unallocated memory
  60 // at the beginning of BigBuf is always for traces/samples
  61 uint8_t *BigBuf_malloc(uint16_t chunksize)
  62 {
  63         if (BigBuf_hi - chunksize < 0) {
  64                 return NULL;                                                    // no memory left
  65         } else {
  66                 chunksize = (chunksize + 3) & 0xfffc;   // round to next multiple of 4
  67                 BigBuf_hi -= chunksize;                                 // aligned to 4 Byte boundary
  68                 return (uint8_t *)BigBuf + BigBuf_hi;
  69         }
  70 }
  71
  72
  73 // free ALL allocated chunks. The whole BigBuf is available for traces or samples again.
  74 void BigBuf_free(void)
  75 {
  76         BigBuf_hi = BIGBUF_SIZE;
  77         emulator_memory = NULL;
  78 }
  79
  80
  81 // free allocated chunks EXCEPT the emulator memory
  82 void BigBuf_free_keep_EM(void)
  83 {
  84         if (emulator_memory != NULL) {
  85                 BigBuf_hi = emulator_memory - (uint8_t *)BigBuf;
  86         } else {
  87                 BigBuf_hi = BIGBUF_SIZE;
  88         }
  89 }
  90
  91
  92 // return the maximum trace length (i.e. the unallocated size of BigBuf)
  93 uint16_t BigBuf_max_traceLen(void)
  94 {
  95         return BigBuf_hi;
  96 }
  97
  98 void clear_trace() {
  99         uint8_t *trace = BigBuf_get_addr();
 100         uint16_t max_traceLen = BigBuf_max_traceLen();
 101         memset(trace, 0x44, max_traceLen);
 102         traceLen = 0;
 103 }
 104
 105 void set_tracing(bool enable) {
 106         tracing = enable;
 107 }
 108
 109 /**
 110  * Get the number of bytes traced
 111  * @return
 112  */
 113 uint16_t BigBuf_get_traceLen(void)
 114 {
 115         return traceLen;
 116 }
 117
 118 /**
 119   This is a function to store traces. All protocols can use this generic tracer-function.
 120   The traces produced by calling this function can be fetched on the client-side
 121   by 'hf list raw', alternatively 'hf list <proto>' for protocol-specific
 122   annotation of commands/responses.
 123
 124 **/
 125 bool RAMFUNC LogTrace(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_start, uint32_t timestamp_end, uint8_t *parity, bool readerToTag)
 126 {
 127         if (!tracing) return FALSE;
 128
 129         uint8_t *trace = BigBuf_get_addr();
 130
 131         uint16_t num_paritybytes = (iLen-1)/8 + 1;      // number of valid paritybytes in *parity
 132         uint16_t duration = timestamp_end - timestamp_start;
 133
 134         // Return when trace is full
 135         uint16_t max_traceLen = BigBuf_max_traceLen();
 136
 137         if (traceLen + sizeof(iLen) + sizeof(timestamp_start) + sizeof(duration) + num_paritybytes + iLen >= max_traceLen) {
 138                 tracing = FALSE;        // don't trace any more
 139                 return FALSE;
 140         }
 141         // Traceformat:
 142         // 32 bits timestamp (little endian)
 143         // 16 bits duration (little endian)
 144         // 16 bits data length (little endian, Highest Bit used as readerToTag flag)
 145         // y Bytes data
 146         // x Bytes parity (one byte per 8 bytes data)
 147
 148         // timestamp (start)
 149         trace[traceLen++] = ((timestamp_start >> 0) & 0xff);
 150         trace[traceLen++] = ((timestamp_start >> 8) & 0xff);
 151         trace[traceLen++] = ((timestamp_start >> 16) & 0xff);
 152         trace[traceLen++] = ((timestamp_start >> 24) & 0xff);
 153
 154         // duration
 155         trace[traceLen++] = ((duration >> 0) & 0xff);
 156         trace[traceLen++] = ((duration >> 8) & 0xff);
 157
 158         // data length
 159         trace[traceLen++] = ((iLen >> 0) & 0xff);
 160         trace[traceLen++] = ((iLen >> 8) & 0xff);
 161
 162         // readerToTag flag
 163         if (!readerToTag) {
 164                 trace[traceLen - 1] |= 0x80;
 165         }
 166
 167         // data bytes
 168         if (btBytes != NULL && iLen != 0) {
 169                 memcpy(trace + traceLen, btBytes, iLen);
 170         }
 171         traceLen += iLen;
 172
 173         // parity bytes
 174         if (parity != NULL && iLen != 0) {
 175                 memcpy(trace + traceLen, parity, num_paritybytes);
 176         }
 177         traceLen += num_paritybytes;
 178
 179         if(traceLen +4 < max_traceLen)
 180         {       //If it hadn't been cleared, for whatever reason..
 181                 memset(trace+traceLen,0x44, 4);
 182         }
 183
 184         return TRUE;
 185 }
 186 int LogTraceHitag(const uint8_t * btBytes, int iBits, int iSamples, uint32_t dwParity, int readerToTag)
 187 {
 188         /**
 189           Todo, rewrite the logger to use the generic functionality instead. It should be noted, however,
 190           that this logger takes number of bits as argument, not number of bytes.
 191           **/
 192
 193         if (!tracing) return FALSE;
 194
 195         uint8_t *trace = BigBuf_get_addr();
 196         uint16_t iLen = nbytes(iBits);
 197         // Return when trace is full
 198         if (traceLen + sizeof(rsamples) + sizeof(dwParity) + sizeof(iBits) + iLen > BigBuf_max_traceLen()) return FALSE;
 199
 200         //Hitag traces appear to use this traceformat:
 201         // 32 bits timestamp (little endian,Highest Bit used as readerToTag flag)
 202         // 32 bits parity
 203         // 8 bits size (number of bits in the trace entry, not number of bytes)
 204         // y Bytes data
 205
 206         rsamples += iSamples;
 207         trace[traceLen++] = ((rsamples >> 0) & 0xff);
 208         trace[traceLen++] = ((rsamples >> 8) & 0xff);
 209         trace[traceLen++] = ((rsamples >> 16) & 0xff);
 210         trace[traceLen++] = ((rsamples >> 24) & 0xff);
 211
 212         if (!readerToTag) {
 213                 trace[traceLen - 1] |= 0x80;
 214         }
 215
 216         trace[traceLen++] = ((dwParity >> 0) & 0xff);
 217         trace[traceLen++] = ((dwParity >> 8) & 0xff);
 218         trace[traceLen++] = ((dwParity >> 16) & 0xff);
 219         trace[traceLen++] = ((dwParity >> 24) & 0xff);
 220         trace[traceLen++] = iBits;
 221
 222         memcpy(trace + traceLen, btBytes, iLen);
 223         traceLen += iLen;
 224
 225         return TRUE;
 226 }